This invention relates to lapped multiplanar surfacing for structures such as buildings, and in particular to lapped multiplanar surfacing having interfitted sections with fastener or anchor strips each securing plural sections at the junctures between sections. Specifically, the invention is directed to horizontal siding panel systems having vertical stringers with resilient clips for securing the panels to a wall or the like.
Horizontally elongated siding panels such as roll-formed sheet metal (e.g. aluminum) panels or molded plastic (e.g. vinyl) panels are widely employed for cladding exterior walls of buildings. Typically, the panels are mounted one above another on a wall in parallel, overlapping, interlocked relation with the surface of each panel sloping downwardly and outwardly so as to simulate the appearance of clapboards or other conventional wooden siding, and are attached to the wall at their top margins by suitable fasteners. Each panel has an outwardly projecting lip along its top margin, and an inwardly bent, upwardly opening channel flange at its bottom margin for overlying and interlocking with the lip of the next lower panel on the wall to secure the panel bottom edge (with the panel surface spaced from the surface of the lower panel) and to conceal the fasteners that hold the lower panel.
It will be understood that terms such as "inner" or "inwardly" and "outer" or "outwardly" herein designate directions respectively toward and away from the wall on which a panel is mounted, and that these terms, as well as terms such as "upper" or "top" and "lower" or "bottom," are used with reference to the orientation of a panel when mounted on a wall with the long dimension of the panel extending horizontally; also, that "wall" includes sloping surfaces such as roofs as well as vertical wall surfaces.
Siding panels of the type described above have conventionally been secured to walls by fasteners such as nails driven through a flat nailing flange (which may have prepunched nail holes) provided at the panel top margin above the locking lip, or alternatively by plural small individual resilient clips which engage the locking lips of the panels and are nailed or otherwise fastened on the wall. These mounting arrangements are disadvantageous in that it is difficult to achieve proper positioning and alignment of the successive courses of panels, especially when installation is being performed by homeowners without experience or special equipment.
Accordingly, vertical stringers have been devised to facilitate mounting of horizontal siding panels. A typical commercially available vertical stringer for this purpose is a vertically elongated roll-formed thin metal strip having a plurality of preformed integral resilient clips, opening downwardly, located at vertically spaced intervals along its length. The clips are produced by striking out portions of the central web of the metal strip and forming the struckout portions to a shape suitable for engaging and holding the locking lips of panels of the above-described type; the spacing between successive clips on a stringer is equal to the spacing between the lips of adjacent (lower and upper) panels when the panels are interlocked. In use, a plurality of these stringers are nailed or otherwise fastened side by side on a wall in vertically oriented, parallel, spaced relation (e.g. 16 inches or 24 inches apart on centers) with their respective clips horizontally aligned, i.e. with the lowermost clips of all the stringers lying in a first common horizontal line, the next higher clips of all the stringers lying in a second common horizontal line, and so forth, each stringer extending from the lower edge of the wall to the top of the wall. Alignment of the stringers is achieved by first mounting a conventional horizontal starter strip along the lower edge of the wall and then engaging the lowermost clip of each stringer with the starter strip before nailing the thus-aligned stringer to the wall in a vertical position. The panels are successively snapped into place on the stringers, beginning with the lowermost course of panels, by inserting the top margin and lip of a panel into a horizontal row of clips respectively formed on adjacent stringers while simultaneously fitting the bottom marginal flange of the panel over the lip of the next lower (already mounted) panel; each panel is held in place by at least two (usually several more than two) clips at the top and by interlocking with the next lower panel at the bottom. The preformed, regularly spaced clips assure that all the panels thus installed are properly positioned and aligned in the array of panels.
Nevertheless, currently available types of vertical stringers present other problems. Their design requires that the installer position the top locking lip and the bottom locking flange of a panel for simultaneously engagement respectively with a row of stringer clips and with the lip of the already-mounted next lower panel, while holding the panel in against the stringers and raising it into locking position. Owing to the complexity of this operation, the panel often fails to engage one or more of the stringer clips that are to hold it, and must then be removed from engagement with the rest of the clips before it can be repositioned for proper mounting; such removal is difficult and often distorts or otherwise damages at least some of the clips.
A further problem, encountered in use of vertical stringers with plastic siding panels, is that plastic panels sometimes tend to be less stably retained by clip and interlock arrangements than metal panels, owing to their relatively greater flexibility. Moreover, the central webs of plastic panels (between the lips and bottom flanges) tend to depart in varying degrees from true planar configuration. Although horizontal siding panels of the type herein considered are usually quite long (a representative example of panel dimensions being 12 feet 6 inches in horizontal length, and eight inches in exposed vertical height after installation), the length of many walls requires installation of two or more panels side by side in a single course; and where the butt ends of adjacent panels meet in the same course, differing degrees of distortion of their respective central webs produce an undesirable discontinuity in appearance.